The invention relates to a system for protecting products against imitation as well as to check the authenticity of products and/or to detect product imitations.
Very few products are protected against imitations. Increasingly better technical options and involved methods used by the imitators result in ever better imitations. Consumers and dealers can rarely distinguish at first glance between the original product and the imitated product. The result is a drop in turnover, liability claims, and loss of image for the producers of proprietary goods. The conventional identification features of many brand names, for example labels and packaging, no longer present obstacles for imitators. In addition to the product itself, its complete presentation is imitated these days.
Attempts have been made to counter these imitations with the aid of special protective features, which require a high technical and financial expenditure and for the most part can be produced only by businesses specializing in this type of work. The product, or its packaging, or the accompanying documents are provided at the production stage already with protective features such as safeguarding threads, planchets, and the like, which are provided with one or several substances having a physical or chemical property that can be checked visually or with a machine, e.g. fluorescence or magnetism. Hologram labels having a color effect which depends on the viewing angle and cannot be reproduced by copiers, represent a favorite protection feature that is affixed to the product or its packaging. The known measures for increasing the protection against imitation and increasing the rate of detection of imitations furthermore include the use of microtext, guilloche print, kinegrams, transponders, and the like.
However, the protective features used in each case make sense only for a restricted number of products, for example depending on legal, medical, or even economic requirements. Technologically involved measures may also require sensors and measuring devices, which are not readily available, for checking the imitations. Conversely, the simpler and cheaper the production of the protective feature, the smaller the technical advantage, upon which the protective feature is based, as compared to the imitator.
The so-called unique-card-method is known from German Unexamined Published Application DE-OS 27 34 456. With this method, an open information such as an account number and/or a personalizing information is combined with a unique number to form an encoded information, wherein this information is then input into a recording medium. During the reading and checking of the recording medium, the open information is initially derived again from the coded information and the unique number. This open information is then compared to the open information recorded on the recording medium. This method is used to protect ID cards and documents.
German Unexamined Published Application DE 28 26 469 C2 discloses a method and a device for protecting documents, for which an identification number is encoded and recorded on the document. During the check, the coded identification number read out of the document is decoded and is compared to the original identification number.
It is the object of the present invention to propose a general product protection method which can in principle be used for all types of products, has the lowest possible requirements with regard to checking, and is cost-effective.
This object is solved according to the invention with a method for producing a product protection identification as defined in claim 1, with a product piece that cannot be imitated as defined in claim 12, and with a method for checking the authenticity of a product piece as defined in claim 23, as well as with a product protection server structure as defined in claim 37. Advantageous modifications of the invention follow from the dependent claims. Computer program products for implementing the method according to the invention follow from claims 44, 45.
With the method according to the invention, a product-specific identification sequence is initially determined for each product piece in order to generate a product protection identification which is affixed to or on the product piece, thus ensuring the authenticity of a product piece. The product-specific identification sequence or a sequence derived from it is encoded with the aid of an encoding method (F1), using a secret encoding sequence (B), wherein a coded check sequence is generated. A product control sequence comprising the coded check sequence or a sequence derived from it is affixed on or to the product piece.
In order to distinguish original products from imitations, a secret encoding sequence (B) as well as an encoding method (F1) is made available to the producer of a product, which enables the producer to convert the respective product-specific identification sequence into a coded check sequence which is then affixed to or on the product piece. Instead of ensuring the authenticity of a product piece with the aid of physical, measuring-technical, or chemical product features, the method according to the invention identifies imitations with the aid of the cryptographically generated product control sequence. A protective feature can thus be made available, which can be used for all product groups because it is not dependent on physical or chemical product characteristics. No sensors or measuring devices are required for testing the authenticity of a product, but only a check of the authenticity of the product control sequence. Since only an encoding method is used in place of complicated protective features (for example microtext, guilloche print, kinegrams, transponders, etc.), the method according to the invention is also much more cost-effective than the protective features employed so far.
It is advantageous if the coded check sequence (C) cannot be generated from the product-specific identification sequence (K) without knowledge of the secret encoding sequence (B). Only producers who possess the secret encoding sequence can generate product control sequences for the product pieces they produce. The secret encoding sequence (B) cannot be derived from the product control sequences of products that are commercially available.
According to a different advantageous embodiment of the invention, the product control sequence comprises the product-specific identification sequence (K) in addition to the encoded check sequence (C) or the sequence derived from it. With this embodiment of the invention, the product control sequence contains the non-encoded identification sequence (K) as well as the coded check sequence (C). Thus, the authenticity of the product control sequence can be tested by checking whether the two segments of the product control sequence match, for example by realizing a decoding of the coded check sequence (C) or an encoding of the product-specific identification sequence (K).
It is furthermore advantageous if the serial number for the product piece is used for the product-specific identification sequence (K). The serial number is generated during the production and permits allocating a product piece to a specific batch. In particular when producing higher-quality products, it is standard practice to affix a serial number. The serial number can be supplemented easily by adding the encoded check sequence in order to generate the product control sequence according to the invention.
According to a different and advantageous embodiment of the invention, the secret encoding sequence (B) is the secret code for a symmetric encoding method. Symmetric encoding methods are also referred to as single-key systems or secret key systems. A secret code, meaning a secret encoding bit sequence, is used to encode a product-specific identification sequence or a sequence derived from it. With symmetric encoding methods, the encoded sequence generated in this way can only be decoded with knowledge of this secret code, even if the encoding and decoding methods are generally known. Conversely, if the decoding of an encoded sequence with a secret code provides the underlying non-encoded sequence, this sequence can have been encoded only with knowledge of this secret code.
Symmetric methods can generally be realized very quickly and with little expenditure, using hardware or software. Using symmetric encoding methods furthermore has the advantage that the generally used code lengths and block lengths are relatively short. As a result, the generated check sequences and the product control sequences are also relatively short and can be affixed easily to the product pieces.
In particular, it is advantageous if the symmetric encoding method is selected from among the following encoding methods: Triple-DES, IDEA, CAST-128, Blowfish, RC5, f8, Rijndael.
Alternatively, it is an advantage if the secret encoding sequence (B) is the secret code for an asymmetric encoding method. Asymmetric encoding methods, which are also called two-key or public-key methods, use code pairs formed with a public code and a private code. Since the private code cannot be computed from the public code with the computer capacity available at the present time, the public code can be made public. With the product protection method according to the invention, it offers itself to use the secret code on the side of the producer for encoding the identification sequence or a sequence derived from it. The public code, which can be made freely available to all communication participants without secrecy requirements, can thus be used for testing the product authenticity. In particular, this allows a decentralized testing which can be carried out by the participating dealers and consumers at many different locations. All dealers can be provided with the public code required for the decoding operation.
It is particularly advantageous in that case if the asymmetric encoding method is selected from among the following encoding methods: RSA, ElGamal, DSA, ECC.
It is also advantageous if the product-specific identification sequence (K) is converted with a first hash method (h1) into a first hash sequence (h1(K)), prior to the encoding, wherein the encoded check sequence (C) is generated by encoding the first hash sequence (1(K)) with the secret encoding sequence (B). Thus, a hash method (h1) is initially applied to the product-specific identification sequence and the resulting hash sequence is then encoded. The protection for the encoding that is realized can be increased on the whole by using a hash method in addition to the encoding operation. It is therefore nearly impossible for an imitator to determine the underlying encoding method (F1) as well as the underlying secret encoding sequence (B) by using the encoded check sequence (C).
It is furthermore advantageous if, following the encoding, the encoded check sequence (C) is converted with the aid of a second hash method (h2) to a second hash sequence (h2(C)), which is then affixed on or to the product piece as component of the product control sequence. With the aid of a second hash method (h2), applied after the encoding operation, it is possible to shorten extremely long encoded check sequences (C) before they are affixed to or on the product piece as part of the product control sequence. In particular when using asymmetric encoding methods, which are characterized by long code lengths and block lengths, long encoded check sequences are created, which make it appear useful to apply a second hash method, wherein the second hash method on the whole increases the protection of the coding.
Selecting the first and second hash methods from among the following: MD 5, SHA-1, RIPE-MD 160, MDC-2 is particularly advantageous.
The imitation-proof product piece according to the invention comprises a product control sequence affixed to or on the product piece, which includes an encoded check sequence (C) or a sequence derived from it. The encoded check sequence (C) is generated specifically for the product piece by encoding a product-specific identification sequence (K) or a sequence derived from it with the aid of an encoding method (F1) and using a secret encoding sequence (B). In place of using the most expensive and hard to produce protective features possible, the protection against imitation for the product piece according to the invention is ensured by using an encoding method (F1) and the use of a secret encoding sequence (B). Generating and affixing the product control sequence to the product piece to be protected causes little expenditure and is cost-effective.
According to one advantageous embodiment of the invention, the product control sequence is affixed to the product piece in the form of an alpha-numerical character string. For example, the coded check sequence and the product control sequence can be generated in the form of bit sequences, wherein the product control sequence can be reproduced as a number sequence, with numbers ranging from 0 to 9, or as a sequence of ASCII characters, or as an optional alpha-numerical character string, and can be affixed to the product piece.
It is furthermore advantageous if the product control sequence is affixed to the product piece in a machine-readable form. For example, the product control sequence could be affixed to the product piece in the form of a universal unit code (barcode) or as machine-readable text. The product control sequence could also be stored on a magnetic strip, a storage chip, or any other electronic medium that is connected with the product, the product packaging, or the accompanying documents. With this type of embodiment of the invention, longer product control sequences can also be processed because no typing-in is required.
It is a further advantage if the product control sequence is affixed to the product piece as visually readable text. With this embodiment of the invention, the product control sequence can be checked by using a keyboard to type in the product control sequence.
According to a different advantageous embodiment of the invention, the product control sequence is affixed to a document enclosed with the product piece or to the packaging. In this way, a long product control sequence can be enclosed with the product without damaging the product appearance.
With the method according to the invention for checking the authenticity of a product piece, the authenticity of the product piece is checked via the Internet and a product control sequence that is affixed to or on the product piece. The product control sequence is detected in that case by the person submitting the control request and is transmitted via the Internet to a product protection server structure. On the side of the product protection server structure, a coded check sequence (C) that is derived from the product control sequence is decoded by means of a decoding method (F2) and a decoding sequence (A), thereby generating a decoded check sequence. The decoding sequence (A) in this case forms a complementary code pair together with the encoding sequence (B), used for the encoding. The authenticity of the decoded check sequence or a sequence derived from it is checked and the result of the authenticity check is then transmitted via the Internet to the person who submitted the control request.
A dealer wanting to check the authenticity of product pieces can, for example, transmit the corresponding product control sequences via his/her Internet browser to the product protection server structure. There, the decoding of the encoded check sequence (C) and the authenticity check are carried out, with the advantage that no local devices are needed on the side of the dealer for checking the product authenticity. Sensors and measuring devices, such as provided according to prior art for checking physical or chemical protective features, are not needed with the method according to the invention. The total investment for implementing the product protection system according to the invention is therefore minimal. Since the decoding is not realized locally, but centrally on the side of the product protection server structure, a secret or a public code can optionally be used as decoding sequence (A).
According to one advantageous embodiment of the invention, the decoding sequence (A) is the secret code for a symmetric encoding method. The use of a symmetric encoding method has the advantage of a relatively short code length as well as block length. Since the decoding of all control requests is realized centrally by the product protection server structure, keeping the decoding sequence (A) secret can be ensured with appropriate measures, for example by using firewalls, separate crypto servers, and the like. A further advantage of using a symmetric method is that the time required for each decoding operation is very short.
Alternatively, the public code for an asymmetric encoding method is advantageously used for the decoding sequence (A). When using an asymmetric encoding method, no special arrangements are required to keep the public code, used for the decoding, a secret. With asymmetric encoding methods, the secret encoding sequence (B) cannot be derived either from the decoding method (F2), or the decoding sequence (A), or from various random samples of pairs of non-encoded and encoded information bits. Even if an imitator were to obtain access to the public code, the decoding method, as well as various valid product control sequences, the imitator could not derive the secrete encoding sequence (B) from this. The imitator himself/herself therefore cannot generate valid product control sequences.
It is furthermore advantageous if the encoded check sequence (C) forms a sequence segment of the product control sequence or can be derived from a sequence segment of the product control sequence by applying a hash reversing function (h2−1). If, during the generating of the product control sequence, the encoded check sequence (C) was additional converted by means of a second hash method (h2) to a second hash sequence (h2(C)), then a hash reversing function (h2−1) must first be applied on the side of the product protection server structure to the respective segment of the product control sequence to obtain the coded check sequence (C). The coded check sequence (C) is subsequently decoded.
It is furthermore advantageous if the decoded check sequence represents a product-specific identification sequence (K) or can be converted to a product-specific identification sequence (K) by applying a hash reversing function (h1−1). If, during the generating of the product control sequence, the product-specific identification sequence (K) was converted to a first hash sequence (h1(K)), prior to the decoding and by means of a first hash method (h1), then a hash reversing function (h1−1) must be applied after the decoding to the decoded check sequence, on the side of the product protection server structure, in order to obtain the individual identification sequence (K).
According to a different advantageous embodiment of the invention, the authenticity of the decoded check sequence or a sequence derived from it is checked by comparing the decoded check sequence or the sequence derived from it with a product-specific identification code (K), forming a segment of the product control sequence, or a hash sequence (h1(K)) derived from it. With this embodiment of the invention, the product control sequence comprises all information required for detecting the authenticity. The authenticity of the product control sequence can therefore be determined solely on the basis of the product control sequence itself, without requiring external information.
Alternatively, it is an advantage if the authenticity of the decoded check sequence or a sequence derived from it is checked by checking whether the decoded check sequence or the sequence derived from it matches previously determined allotments. With this embodiment of the invention, all producers are provided with sequence allotments ahead of time. To check the authenticity of a decoded check sequence or a sequence derived from it, it is determined whether or not this sequence matches an allotment assigned to one of the producers. The advantage of this step is that for this embodiment of the invention, the product control sequence does not have to comprise the non-encoded information. The product control sequence only needs to comprise the encoded information. For that reason, relatively short product control sequences are sufficient for this embodiment of the invention.
It is advantageous if the legitimacy of the person submitting the control request is checked within the framework of checking a product control sequence. Only authorized dealers are permitted to inquire about product control sequences. In addition, the path of the checked product pieces can be followed by requesting the legitimacy of the person submitting the request.
According to another advantageous embodiment of the invention, a database entry is made into a login database within the framework of a request for a product control sequence, thus making it possible to put together a login database which comprises database entries for all previously checked product control sequences. Assuming an imitator obtains a series of product control sequences for original products and affixes these product control sequences to the imitated goods, this cryptographic method would show that the respective product control sequence is authentic. However we now have several product pieces with identical product control sequences on the market. A multiple use of product control sequences of this type can be uncovered with the aid of the login database.
It is advantageous if a login database is requested to determine whether earlier requests were submitted concerning the product control sequence of the product piece. Assuming a first dealer submits a control request for the first product pieces received and checks the product control sequences affixed to the product pieces. The cryptographic method supplies the result that the product control sequences are authentic and, in addition, enters the data for these product control sequences in the login database. If a second dealer submits control requests at a later time for second product pieces that are provided with the identical product control sequences, it can be determined with the aid of the login database that another dealer previously submitted control requests for these product control sequences. Two options are then available: the product of the first dealer was the original product, and the second dealer had the imitation, or vice versa. If a multiple use is detected, the product available to the dealer submitting the request can either be an imitation or it may have served as modal for the imitation.
An effective protection can be achieved on the whole by combining the use of a cryptographic method with the establishment of a log for the various requests submitted by the various dealers.
It advantageous to compare at least one of the following: product control sequence, product-specific identification sequence (K), encoded check sequence (C), decoded check sequence, or a sequence derived from it to database entries in the login database. In the process, the product piece is identified as either an imitation or a model for an imitation if at least one match is detected. A specific product piece can be identified with any of the aforementioned sequences because each of these sequences is specific to the respective product piece. If a multiple use is detected for the respectively used sequence, it indicates the presence of either an imitation or an original product which served as model for an imitation.
It is advantageous if a database entry for a control request also contains the date on which the control request was submitted. In addition, it is advantageous if a database entry contains the identity of the person submitting the control request. Upon detecting a multiple use of a product-specific sequence, the path taken by the imitation products can be traced back, using the information entered for the participating dealers and the points in time at which the dealers submitted the control requests.
The product protection server structure according to the invention makes it possible to implement a product production gateway for checking the authenticity of product pieces with the aid of a product control sequence affixed to or on the product piece. The product protection server structure comprises a web server module, which makes available websites of the product protection gateway via the Internet. A product control sequence is transmitted via the Internet to the web server module and the result of the authenticity check is transmitted via the Internet to the person submitting the control request. The product protection server structure further comprises a cryptographic module for decoding an encoded check sequence (C), derived from the product control sequence, by means of a decoding method (F2) and using a decoding sequence (A), thus generating a decoded check sequence. A complementary code pair is thus formed with the decoding sequence (A) and the encoding sequence (B), used for the encoding. The authenticity of the decoded check sequence or a sequence derived from it is checked with the cryptographic module.
It is advantageous if the product protection server structure comprises a login database, which contains a database entry at least for each product control sequence for which the authenticity was determined. With the aid of such a login database, it is possible to prove the repeated use of product control sequences, an indication that a product imitation is present.
The method used to generate a product-protection identification can be realized with a computer program product, provided with means for implementing the corresponding method steps on a computer, a signal processor, or the like. The method for checking the authenticity of a product piece can also be realized with the aid of a computer program product, which is provided with means for realizing corresponding method steps on a computer, a digital signal processor, or the like.